Chrysler Repair Questions? Ask a Mechanic for Answers ASAP
Hi, I am Mike, welcome. I'm reviewing your question.
I want to pull up the wiring diagram and want to be sure. With that done said, I see there are actually 2 different 2.7 engines, one with a code of R and one with a T, so if you could tell me the 8th digit of the vehicle vin number if it's an R or a T?
Ok, got it. Now, the red wire at the alternator make sure it is has 12 volts with key off engine not running.
Then check the ground wire, it's the black/tan wire at pin 1 of the alternator, so just move your voltmeter ground test lead to that black/tan wire while keeping the positive on that red wire if it had 12 volts before and it should still rad 12 volts.
Then start the engine, rev it up to about 2,000 rpm and check the voltage again at the red wire and you can ground the voltmeter wherever, on that black/tan or a metal ground or the negative battery post but now the voltmeter should read like 14 volts at the back of the alternator at 2,000 rpm. If not, let me know. If it does check again the voltage making it to the positive battery post. If it is only 12 there, then that red wire/cable from the alternator to the positive battery post is bad.
If it still only puts out 12 volts at the back of the alternator at the red wire and everything else checked out ok, then the PCM driver obviously isn't providing the ground for the field. So if that is the case begin by checking those fuses, #14 in the PDC at left front fender and the 325 same spot. If they both are good, try a new auto-shut down relay, also in the PDC. make sure you use the voltmeter when checking the fuses, too and the #14 should be hot on both sides even with key off, but the #25 is powered from the auto shut-down relay, so the key will most likely have to be on run and maybe even with the engine running.
Here is that wiring diagram,
Yes, keep the voltmeter positive lead on the red wire and move the voltmeter negative test lead to the black/ tan wire cause that is the ground wire. That would test to make sure the ground wire is ok and grounding.
Ah ha. That means that ground is bad. Maybe it is just unhooked at the other end. Check at the left front strut tower for the ground, it should have a black wire cause the wire changes color.
wait, You are not supposed to be checking voltage there, that is a ground. Place the negative voltmeter lead on that black/tan wire at the positive test lead where it was on that red wire.
Yes, that is it, the black/tan wire. You did this nd now the voltmeter reads 0 volts?
Check this spot for that G103 ground and see if it is unhooked. If not, unhook it and unhook the black/tan wire a the alternator and use an ohmmeter on both ends and check if it makes continuity or not.
Ok, you found it, now check it with an ohmmeter.
Or if you don't have an ohmmeter just hook your voltmeter back up to check that red wire and this time run a jumper wire from that black/tan wire to ground or the negative battery post and see now if the alternator puts out 14 volts when reved to 2,000 rpm. If so, that ground is bad.
Check them both. Set the meter on OHMs, the lowest setting. Say like around 5 ohms. Or whatever is closet to that. Then touch the leads together, look at the meter that is what it would show if the wire is intact when you use it on the wire. now move the test leads apart, this shows an open or bad circuit. Now test that wire with the ohmmeter.
Yes, the must be a digital ohmmeter then. Then 0 is what it is supposed to say when checking both ends of that wire, or damn close to 0 maybe like 5 ohms at the most. So, let me know.
No, you have to touch the test lead to either the metal end of the wire or any copper wire strands that might be exposed, Not just the plastic cause that is probably an insulator.
Is the plastic where you put the test lead when using the voltmeter? If so, you must touch the metal end of the wire, or if there is none, then you will have to poke through the wire insulation and get to that copper wire strands.
but when using the ohmmeter the wire has to be disconnected anyhow at the alternator, so you should not have to poke through, just touch it to the end of the wire at the metal end.
Yes, then you will have to poke through, but before that, check those fuses, maybe it is just a fuse. I hate to poke through wire insulation cause water can get in. If you must, make sure you tape it up afterward with electrical tape.
Check them fuses now.
No we did not. Check the fuses first.
ground the negative to a metal ground and touch the positive to each side of the fuse where the metal is exposed on the edge of the fuse.
Are the labeled in any way at all?
This should help, it shows the numbers
Yes. First just look at both t see if either are blown. Then test both sides, 14 hot all the time and 25 with key on run.
I tell you what, just try swapping that auto shut down relay with the headlamp washer relay, then go back and check if the alternator is putting out 14 volts now at 2,000 rpm.
If there is no metal tips exposed on the edges of the fuse, then you would have to remove it and test the empty socket, but then again, only one terminal in the socket can be hot that way
What do you mean still nothing? The voltmeter has to read something, is it 12 volts now at the red wire or is it really 0 volts?
Ok, about all you can do then install new fuses in those 2 spots, hope for the best and if it still don't work, have someone retrieve those trouble codes cause you may be looking at a faulty PCM.
Disconnect both ends and use the ohmmeter and you have to touch the metal ends on both ends.
What black wire and from what pin?
That isn't a black wire at the alternator is it? isn't it a black/tan wire?
Ok, yes than the black wire, I suspect maybe you cannot see the tan stripe.
Yes a photo, please
Yeah, I see the tan stripe on that black wire but it is very faint, but it is there. That is the one.
That plastic piece may unclip an open a bit so you can test, try to open that plastic piece.
Unplug it if you are going to use the ohmmeter but if using the voltmeter the wire will have to be still hooked up, I thought that maybe the plastic piece was just a protector or sorts that could be opened up to expose the wire end.
Disconnect that black wire at that ground g103 and use the ohmmeter and check if that ground wire is open or closed. Actually, for now just leave that G103 hooked up and test the resistance using the ohmmeter between the black/tan wire at the alternator and the battery negative post. Like that it should read less than 5 ohms.
I believe if you momentarily jump that green wire to a metal ground while the engine is idling, the alternator should put out the maximum voltage, so do you want to try that?
If when you do this and it puts out over 14 volts, then I would summize that the PCM is bad.
First make a jumper wire. Then if you have to unhook that connection at the back of the alternator if you have no exposed metal on the wires. Then you would actually have to make 2 jumper wires, cause you will have to connect that black/tan wire back to where it is supposed to go, Then you can just jump where the green wire connects to the alternator and jump it to a metal ground, so you can just leave the green wire disconnected from the harness for now and the PCM.
Like this it will completely bypass the PCM.
No, leave it off. make 2 jumper wires. One that will hook up to the end of that black/tan wire and the other end of the jumper wire plug onto the spot on the alternator where that black/tan wire goes. Then with a second jumper wire and most likely a much longer one, make it so it plugs into where that green wire goes on the alternator and attach the other end of the long jumper wire to a metal ground or the battery negative post if you make it long enough to reach that.
Are you making jumpers?